Electric wiring strip and method for making same



Feb. 27, 1934.

L. KALISCHER ELECTRIC WIRING STRIP AND METHOD FOR MAKING SAME Filed Oct.15, 1931 6 Sheets-Sheet l U INVENTOR M4 WM 1 ATTORNEY Feb. 27, 1934. L.K

ALISCHER 1,949,077

ELECTRIC WIRING STRIP AND METHOD FOR MAKING SAME Filed Oct. 15, 1931 6Sheets-Sheet 2 INVENTOR aud. (i Kenn-- ATTORNEY 1934. KALISCHER ELECTRICWIRING STRIP AND METHOD FOR MAKING SAME Filed Oct. 15, 1931 6Sheets-Sheet 3 INVENTOR =4. a? ATTbRNEY' Feb. 27, 1934. L. KALISCHER1,949,077

ELECTRIC WIRING STRIP AND METHOD FOR MAKING SAME Filed Oct. 15, 1931 6Sheets-Sheet 5 M ATTORNEY Feb. 27,' 1934. 1.. KALISCHER ,0

ELECTRIC WIRING STRIP AN METHOD FOR MAKING SAME Filed Oct. 15, 1931' 6Sheets-Sheet 6 INVENTOR I Ka-W'AK LJ Zu,

A; ATTORNEY Patented Feb. 21, 1934.

UNITED STATES ELECTRIC WIRING STRIP AND METHOD FOR MAKING SAME LouisKalischer, Brooklyn, N. Y. Application October 15, 1931. Serial No.568,900

Claims.

This invention relates to electric wiring strip and a method for makingthe same. The use of ordinary insulated .wires without any protectivecovering is dangerous. .Efl'orts have been made to 5 avoid the danger ofexposed wiring in various ways, such as encasing the insulated wires inan outer casing or covering of flexible fabric or in rigid stripcasingsof metal comprising a base strip and a cover strip.

One of the objects of the present invention is to provide a simpleinexpensive form of wiring strip in which the wires are fully protectedagainst injury by a metallic casing and which ma be readily installed. I

Wiring strip has been made by rolling the edges of a flat ribbon ofmetal around a pair of insulated wires, themetallic ribbon being wideenough to leave a flat web between the rolled-over edges through whichnails may be driven to attach the strip to the wall or the like. Such anarmored strip is, however, stiff, and cannot, in view of the rolled-overedges, be bent at any considerable angle either in the plane of thecentral part of the strip or in a plane perpendicular thereto. In wiringa house it, is-necessary, however, to make numerous right-angle or othermore or less sharp turns to follow the contour of swell, door, or thelike.

It is not possible practically to cut the formed metallic armoring atthe point where a turn is to be made without injuring the insulation ofthe wires. This is due to the fact that as the edges of the metal ribbonforming the armor are rolled around the insulated wires it is notpossible to insert shears or the like between the metal and theinsulation. The cutting must be done wholly from the outside, and thetool in passing through the metal almost necessarily injures therelatively sort insulation therebeneath. V r) According to the presentinvention, provision is made for making bends in the wiring strip byforming the wiring strip of a plurality of both armored and unarmoredsections of insulated wire arranged alternately, the wires beingcontinuous throughout all sections of the strip and the armor beingpermanently and non-slidably iii secured to the wires in the armoredsections. The

unarmored sections are spaced apart the distance between bends or turns,switches or the like, and

consequently the wiring strips are made to fit the requirements of eachand every installation.

The best method known to me for making a strip having alternate armoredand unarmored sections is to make in the metal ribbon before its edgesare turned about the wires oppositely arranged cutouts at the pointswhere bends are to be made. These cutouts are deep enough so that theintervening metal has a width less than that of completed strip. Hence,when the margins of the metallic ribbon between these cutouts so arerolled over the insulated wires, the portion of such ribbon between thecutouts is unaffected by the rolling action and remains as a flat narrowribbon or web underlying the insulated wires. The wiring strip,therefore, comprises a series of armored sections in which the insulatedwires are fully protected by the rolled margins of the metal ribbonconnected by exposed lengths of insulated wire and narrow underlyingportions of metal. These connecting narrow portions or webs may be cutby shears without injury to the insulated wires, as shears can bereadily inserted between such portions and the insulated wiresthereabove. After the connecting portion has been cut, the adjacentarmored sections of the wiring strip can be placed in any desiredangular position with respect to each other. A cover plate of therequisite angular form is then placed over the exposed portions of thewires and adj acent ends or the armored sections.

It is also desirable that there be loose ends of exposed unarmoredinsulated wires extending from the ends of the wiring strip by which thelatter may be attached to outlet boxes, switches and other parts. 95

Each installation requires bends, outlet boxes, switches, etc., atdifferent varying distances apart, with the result that standard wiringstrip with unarmored sections at fixed regular intervals cannot be used.The wiring strip must be made to suit each installation, preferably onthe spot. A further object of the invention, therefore, is theproduction of a simple and preferably portable machine for making theimproved wiring strip.

A full understanding of the invention can best be given by a detaileddescription of an approved wiring strip and method and machine formaking the same. Such description will now be given in connection withthe accompanying drawings 10 illustrating in the form now consideredbest a machine for use in practicing the new method and producing thenew wiring strips, and illustrating also the new wiring strips. In saiddrawings:

Fig. 1 is a side elevation of the machine;

Fig. 2 is an end view of the machine looking from the right in Fig. 1;

Fig. 3 is a plan view of the machine with parts cut away to show thedriving mechanism for the strip-forming rolls;

Fig. 4 is a vertical section on the line 4-4 of Fig. 3;

Fig. 5 is a vertical section on the line 5-5 of Fig. 3, with parts inelevation; I

Fig. 6 is a detail section on an enlarged scale on the line 6-6 of Fig.3 showing the ribon cutting mechanism;

Fig. 7 is a detail section on an enlarged scale on the line 7--7 of Fig.3 with the feed rolls in elevation;

8 is a detail section on an enlarged scale on the line 8-8 of Fig. 3with the forming roll and wire-feed roll in elevation;

Fig. 9 is a detail section on an enlarged scale on the line 99 of Fig. 3with the forming rolls in elevation;

Fig. 10 is a detail section on an enlarged scale on the line 10l0 ofFig. 3 with the measuring rolls in elevation;

Fig. 11 is a plan view of the fixed horn by which the margins of themetallic ribbon are turned upwardly;

Fig. 12 is an end view of the same from the ribbon receiving end;

Fig. 13 is a section on the line 13-13 of Fig. 11 showing the metallicribbon in position therein;

Fig. '14 is a plan view of the fixed horn by which the margins of theribbon are turned inward over the insulated wires;

Fig. 15 is an end view of the same from the strip-delivering end;

Fig. 16 is a section on the line 16-16 of Fig. 3';

Fig. 17 is a plan view of a piece of the metallic ribbon showing one ofthe cutout portions before the margins of the ribbon have been rolledover the insulated wires;

Fig. 18 is a perspective view or a piece 01' the completed wiring strip;1

Fig. 19 is a plan view of two sections of the wiring strip which havebeen turned to extend at right angles to each other; and

Fig. 20 is a similar view to Fig. 19 with a corner cover attached.

The operating parts of the machine are mounted within or on a frame or acasing 25 which as shown is provided with a pair of depending clamps 26by which the machine may be secured to the edge of a table or bench 27.On top of the casing is a forked bracket, one arm 28 of which carries aspool 29 having a. fiat ribbon 32 of thin metal, such as aluminum, woundthereon, while the other arm 30 carries a pair of spools 31 each ofwhich has an insulated wire 33 wound thereon.

The ribbon 32 passes through the cutout device indicated generally by34. This device is designed to form the cutouts 35, as shown in Fig. 17.It comprises a box 36 bolted onto an extension of the main casing 25 andformed with a rectangularly chambered lower section and an upper sectionwhich has a cylindrical bore extending vertically therethrough. In thisbox the cutter 37 is mounted to be movable vertically. The upper part ofthe cutter is cylindrical and slides in the cylindrical aperture in theupper part of the box. The lower part of the cutter is rectangular insection and slides in the similarly shaped chamber in the lower sectionof the box 36. The cutter, therefore, while free to reciprocatevertically, is restrained from turning or moving laterally. The underface of the cutter has a longitudinal central slot 38 in register with acentral bar 39 of a die-plate 40 (Fig. 6) so that the edges of thecutter on either side of such slot cooperate with the edges of the bar39 to cut the intervening metal ribbon 32 along longitudinal 'cutter. Aspring is provided between the lever and the top of the box 36 to holdthe cutter in elevated position until the handle 41 is depressed.

The ribbon passes from the cutout device to a pair of feed rolls 45, 46formed with knurled peripheries to grip the ribbon. Both of these rollspositively driven by mechanism which will be described later.

The ribbon is fed by the rolls 45, 46 through a fixed forming hornconsisting of three parts 4'7, 48 and 48 connected together by bolts 49and 50. The lower part 4''! is attached to the main casing 25 by a bolt51 and the bolts 49.

The part 47 is recessed at the ribbon-entry end to a depth slightly inexcess of the thickness of the ribbon and to a width slightly in excessof the width of such ribbon (Fig. 12) so that the latter may slidebetween the lower part 47 and the inner portions of the upper parts 48,48. At the ribbon-exit end the lower part is trough shaped, as shown inFigs. 12 and 13, and the upper parts 48, 48 are complementarily shaped.Hence, as the ribbon passes through the forming horn it is given asemi-circular form.

The ribbon, now in semi-circular form, passes on to a pair of rolls 52,53. The lower roll 52 has a wide U-shaped groove 55 in its periphery ofthe width of the completed wiring strip. The upper roll 53 has a centralcylindrical portion 54 adapted to press the central part of the ribbonagainst the roll 52. On either side of the central portion 54 of theroll 53 are grooves 56 having'a .width, depth and radius of curvaturesubstantially equal to that of the insulated wires 33, so that, as thelatter are fed under the roll 53, the contour of the roll plus the wiresis substantially complementary to that of the U-shaped groove 55 in theroll 52. The metal ribbon is, therefore, bent into U-shaped form, and atthe same time the insulated wires are laid in the corners so formed. Aguide 67 partly encircling the roll 53 is provided for guiding the wires33 to the roll 53. This guide is mounted on the parts 48, 48 to which itis secured by the bolts 50.

The ribbon and wires then pass to a second fixed forming horn consistingof a lower part 57 and two upper parts 58 held together and attached toa bracket 60 on the main casing by bolts 59. As will be seen from Figs.14, 15 and 16, this horn is shaped so as to turn the upwardly extendingmargins 01' the'metal ribbon inwardly over the insulated wires.

Next in series is a pair of rolls 61, 62. The lower roll 61 has a plaincylindrical contour, while the upper roll 62 has two peripheral grooves63 and an intervening cylindrical portion 64. The latter acts to foldthe inner margins of the metal ribbon downwardly around the insulatedwires and so complete the wiring strip. As the lower roll 61 has a plaincylindrical contour, the lower parts of the outer rounded portions orthe metallic ribbon are forced outwardly and downwardly until theyassume the right-angled crosssectional form shown more particularly inFigs.

. frame 25.

9 and 10. The form of wiring strip so produced has the advantage that itwill fit snugly against a flat surface without leaving cracks or cornersfor the accumulation of dust and dirt.

The wiring strip then passes between a pair of draw rolls 65, .66,provided with knurled peripheries to enable them to grip the central webof the wiring strip and aid the other rolls in moving the wiring stripand its component parts through the machine. Guide pins 88 aid inkeeping the wiring strip in position laterally.

The lower roll of each of the four pairs above described, viz: 45, 52,61 and 65, is mounted on a shaft journaled in fixed bearings in the mainOne of these shafts 68, the one on which the roll 52 is mounted, extendsbeyond the rear wall of the frame or casing and is provided with anoperating handle or crank 69. The other shafts are driven from the shaft68. The rolls of each pair, except and 66, are rotatably connected bysimilar pairs of gears 70, 71, one pair of such gears being shown. inelevation in Fig. 5, so that the upper roll of each pair of rolls,except 66, is driven from the shaft of the lower roll. The gears on theshafts of the several lower rolls 45, 52, 61 and 65 are connected bygears 72, 73 and 74 (see Fig. 3) so that the lower rolls are drivensimultaneously and in the same direction by the rotation of the crank69.

The upper rolls 46, 53, 62 and 66 are each mounted on a shaft 80journaled in a bearing 75 slidable vertically in an aperture in thecasing 25. One of these bearings is shown in plan in Fig. 3 and anotherin section in Fig. 5. Each of these bearings is yieldingly supported bya coil spring 76, and is pressed downwardly thereagainst by a screw 77,resting on a small leaf spring 78 secured to the upper part of thehearing. The screws 77 are provided with handles 83 by which they may beturned to adjust the pressure on the upper rolls.

While it is desirable to have the upper rolls movable verticallywithrespectto the lower rolls, it is not desirable to have the driving gears71 of the rolls 46, 53 and 62 vertically movable. For that reason eachof these upper gears is mounted on a shaft 79 separate from the shaft 80on which the roll is mounted. Each shaft 79 is journaled in fixedbearings on the casing 25 and is connected to the shaft 80 by a doubletongue and groove coupling 81 which permits the shaft 80 to be movedsomewhat out of alignment with the shaft 79,without harm. A shaft 79 isalso connected by a double tongue and groove coupling 81 to the shaft 80of the roll 66. This shaft 79 is in fixed bearings similarly to theshaft 79 which drive the rolls 46, 53 and 62, but there is no gear 71 onthis shaft and it does not drive its roll 66.

It will be noted that mechanically the stripforming machine is verysimple, as all of the rolls are arranged to rotate about parallel axes.an arrangement which greatly facilitates the driving of the rolls from asingle source of power.

Attention is also calledto the fact that the first fixed forming devicemoves the margins of the metallic ribbon inwardly and upwardlytransversely of the ribbon. The first pair of forming rolls is employedto complete the bending of the margins of the metallic ribbon intosubstantially vertical planes. i. e., in a direction perpendicular tothe axes of the forming rolls. The second fixed forming device moves theupper parts of the upturned margins of the ribbon inwardly anddownwardly into a substantially horizontal position. The second pair offorming rolls bend the inturned margins of the ribbon downwardly intosubstantially vertical planes. While the functions of the fixed formingdevices and of the forming rolls overlap, it will be notedthat theprimary function of the former is to move the margins of the ribbonlaterally, i. e.,, in a direction parallel to the axes of the formingrolls, while the primary functionof thelatter is to move the margins ofthe ribbon vertically,- i. e., in a direction perpendicular to the axesof the forming rolls.. The fixed forming devices avoid the necessity ofrolls arranged to rotate about axes perpendicular to the plane of theribbon. The forming rolls aid in moving the strip and its.comp'onentparts through such fixed forming devices as well as doing their part inwrapping the margins of the metallic ribbon around the insulated wires.

The satisfactory use of the machine depends on means shown comprises acounting device 82,

which may be of any suitable construction, arranged on the end of theshaft 79 which is connected to and driven by the upper roll 66. Thisroll has .a knurled periphery so that it will be turned by the passageof the formed wiring strip thereunder and through its coupling 81 andshaft 79 will drive the counting device 82 by which the exact length ofstrip passed between roll 66 and its companion roll 65 will be shown. Asthe roll 66 is not connected by gearing to the other rolls, and notdriven otherwise than by the wiring strip, its rotation will beunaffected by any slip of the other rolls relatively to the metal ribbonand wiring strip made therefrom.

It will be noted that the cutoutmechanism is at a distance from themeasuring roll 66, and, hence, the determination of the time at whichthe cutout device is to be operated involves some such procedure as thefollowing. The distance between the points A and B on the machine (seeFig. 4) is determined and is, say, 15 inches. Then,

when starting to make a wiring strip'of a desired length with cutouts atcertain known points in the length of the strip, the crank is turned tobring the rear edge of a cutout in register with the point A, and thereading on the counting device is noted. To that reading is added thedesired distance between the rear edge of the first cutout and the frontedge of the next cutout, less '15 inches. The algebraic sum of thesequantities is the reading of the counting device at which the cutoutdevice should be operated. The crank is then turn-ed until that readingis reached and a cutout is made. Then the crank is again turned until,as shown by the counting device, a length of the strip equal to thedesired distance to the next cutout has passed the cutting die. Then thecutter is again operated to make another cutout; and this procedure isrepeated until the desired wiring strip has been made.

It will be understood that cutouts of any desired length, in excess ofthat made by a single operation of the cutout device, may be made byrepeated operation of the latter, the strip being moved forward a shortdistance each time. Cutouts of more than the minimumlength are oftenrequired to provide suflicient slack wire for outlet or junction boxes.a

A section of the completed wiring strip, showing a cutout or unarmoredsection and parts of the two adjacent armored sections, is illustratedin Fig. 18. To make a right-angle turn in the plane of the wiring strip,for example, the metallic ribbon is cut by shears along the line CC, atabout the mid-point of the unarmored section. The adjacent armoredsections are then turned at right angles to each other to bring theparts into the position shown in Fig. 19. It, will be noted that the cutends of the metallic ribbon overlap at the point D and therebyelectrically connect the metallic armor of the adjacent sections. Thisis important as it is desirable that the metallic armoring should begrounded electrically. The exposed sections of the wires are thencovered by an angle piece 86 of metal, fibre, Bakelite or other suitablematerial, held in place by screws 87.

Right-angle turns in directions perpendicular to the plane of the wiringstrip can be readily made. If the turn is around a projecting corner,the connecting web of metallic ribbon is either cut and the ends lappedover or else a pleat is formed therein to adjust for the fact that thepath occupied by the wires is longer than that occupied by theconnecting web. If the turn is around a receding corner, the connectingweb must be out if it is desired to avoid buckling of the wires. Withthis type of turn the cut ends of the web are separated, due to the factthat the path occupied by the connecting web is longer than the pathoccupied by the wires. Hence, to complete the grounding of the armoringof the wiring strip, a metal strip or wire must be placed across thespacebetween the out ends of the web.

The metallic armor is usually pliable enough to allow slight angularchanges to be made therein without resort to unarmored sections as abovedescribed.

What is claimed is:

1. A wiring strip, comprising a pair of insulated wires and a metallicribbon having portions of reduced width at predetermined distancestherealong, the margins of the ribbon between such portions of reducedwidth being folded over said wires individually, the ribbon being ofsufficient width to leave an unobstructed central 4 space between thefolded-over portions.

2. A wiring strip, comprising a pair of insulated wires and ametallicribbon having pairs of oppositely arranged marginal cutouts atpredetermined distances therealong, the margins of the ribbon betweensuch cutouts being folded over said wires individually, and the depth ofthe cutouts being such that the intervening portion of metal has a widthnot substantially greater than that of the completed armored sections ofthe wiring strip. A

3. A wiring strip, comprising a pair of insulated wires and a metallicribbon having pairs of oppositely arranged marginal cutouts at prede-1,949,077 7 'termined distances therealong, the depth of each of thecutouts being of the order of magnitude of one third of, the width ofthe metallic ribbon when flat, the margins of the metallic ribbonbetween the cutouts being folded over the insulated wires individually.

4. A wiring strip, comprising a pair of insulated wires and metallicarmor in strip form with its margins folded around each wireindividually and holding the same in fixed parallel relation for aplurality of portions of the length of such wires, such armored portionsbeing at an angle to each other and connected together by unarmored andunsev'ered portions of the wires.

5. A method of making wiring strips, comprising making pairs ofoppositely arranged cutouts in a metallic ribbon at predetermineddistances therealong, and then folding the margins of such ribbonbetween the cutouts over a pair of insulated wires individually.

6. A wiring strip, comprising a pair of insulated wires, and a metallicribbon having end portions of reduced width, the margins of the ribbonbetween such portions of reduced width being folded about said wiresindividually.

'7. A wiring strip, comprising a pair of insulated wires, and a metallicribbon having portions of reduced width at predetermined distancestherealong, the margins of the ribbon between. such portions of reducedwidth being folded about said wires individually.

8. A wiring strip, comprising a pair of insulated wires and a metallicribbon having pairs of oppositely arranged marginal cutouts atpredetermined distances therealong, the margins of the ribbon betweensuch cutouts being folded over said wires individually, and the depth ofthe cutouts being such that the intervening portion of metal has a widthless than that of the armored sections of the wiring strip.

9. The method of making wiring strip comprising cutting out oppositemarginal portions 0!. a metallic ribbon at predetermined distancestherealong, and then wrapping the uncut margins of such ribbon about apair of insulated wires individually, the depth of the cutouts beingsuch that the intervening portion of metal has a width less than that ofthe armored sections of the wiring strip.

10. The method of making wiring strips, comprising cutting out oppositemarginal portions of a metallic ribbon while the latter is stationary,then moving-the ribbon and a pair of superimposed insulated wireslongitudinally and simultaneouslyfolding the margins of the ribbonfollowing such cutouts about the insulated wires individually, stoppingthe ribbon after it has been moved a predetermined distance, and againcutting out opposite =marginal portions of the ribbon.

LOUIS KAI JSCHER.

